As Mamata Banerjee stares at a massive defeat in West Bengal, the spotlight is on the key factors that proved to be her undoing 15 years after she ended the three-decade-long Communist rule. There are striking parallels between this poriborton (change) and the one in 2011, which brought the Trinamool Congress to power. In both, the ruling party’s leadership failed to sense the discontent on the ground and act in time. And Mamata Banerjee, like the Communists, underestimated the growing support for the Opposition. The result: a sweep. This swing was not gradual. In the 2024 Lok Sabha elections, Mamata’s party had bettered its tally by 7, winning 29 out of the 42 parliamentary seats in Bengal. The BJP had taken a hit, its tally going down from 18 to 12.…